5. Constant Esotropia Flashcards
What is constant esotropia?
Esotropia present at all conditions, with or without glasses. Can be unilateral or bilateral.
2types of primary esotropia?
- With accommodative element
- Without accommodative element
Describe with accommodative esotropia?
Onset?
Is surgery an option?
Deviation increases when accommodation is exerted. Commonly large angle esotropia at all distances but bigger on near fixation.
Onset: 18months- 3 years
Surgery: Subjective, depends on how it looks.
What happens when with accommodative ecotopia is corrected?
Angle is reduced, but not eliminated. Hence, no BSV.
Which muscle over acts in with accommodative esotropia?
Inferior oblique overaction
Does with accommodative element esotropia have amblyopia?
If constant strabismus = leads to suppression. Hence, unilateral esotropia = amblyopia.
Esotropia alternates= suppression will alternate and amblyopia unlikely.
What is without accommodative esotropia?
Type of primary esotropia.
Deviation is unaffected by accommodation, large angle esotropia usually larger than 30^ and not associated with RX. Very obvious due to large angle.
Abnormal OKN
Onset of without accommodative esotropia?
4 months
Does without accommodative esotropia alternate?
Alternates with cross fixation
BSV in without accommodative esotropia?
Poor prognosis of BSV even if treated early.
Example of without accommodative esotropia in infants?
Infants with esotropia + nystagmus block
Management of with accommodative esotropia constant esotropia?
Order full Rx- to eliminate as much accommodation as possible (to reduce size of deviation as much as possible- so that fusion can occur). Treat any amblyopia. Surgery is cosmesis with glasses is poor. Size of deviation with glasses will determine if surgery is required.
Why is a px unlikely to have BSV post surgery for with accommodative element constant esotropia?
Age of onset of this condition is between 4 months- 2 years, hence the child will not have had any chance being binocular ever. Hence even after surgery the child will still suppress and fusion is not possible.
What is infantile esotropia with
nystagmus block esotropia?
what happens with cross fixation and how is OKN?
Large angle esotropia, >30^, not associated with RX. Onset: 4 months.
Alternates with cross fixation.
Abnormal OKN.
4 associations of DVD?
- DVD
- Manifest latent nystagmus
- Overacting inferior obliques
- Sometimes exhibits limitation of abduction- cross fixation ductions greater than versions.
Management of infantile esotropia
- Correct any RX (however deviation not related to RX).
- Treat any amblyopia
- Botulinum toxin to or surgery to help with cosmesis.
What is DVD (Dissociated vertical deviation)?
Only happens on dissociation.
Elevation of one eye when it is occluded. Occurs spontaneously. Can be unilateral or bilateral. On CT: When cover is swapped the eye will come down to take up fixation as the other eye is occluded.
DVD vs vertical deviation?
DVD-Elevation of covered eye when occluded. Vertical deviation on cover/ uncover: one eye goes up and other eye moves down.
What is inferior oblique overaction?
Motility disorder characterized by elevation of the affected eye during adduction
What is cross fixation?
Right eye is used to fix when looking into left gaze and the left eye is used when looking into right gaze. Px’s have alternating esotropia.
What is nystagmus block eso syndrome?
Esotropia in patients with congenital nystagmus. Nystagmus reduces when eye are converged- increasing VA.
Characteristics of nystagmus block syndrome?
*Variable often large angle esotropia though both eyes may appear convergent.
*Miosed pupil.
*Often a AHP to maintain fixing eye in adducted position (face turn towards fixing eye).
*Amblyopia is common in the non-fixing eye.
*Nystagmus often increases on lateral gaze.
*Duction usually greater than version.
*Deviation is difficult to measure using PCT as the eye continues to adduct using BO prisms.
Nystagmus block eso syndrome management?
*Correct refractive error and attempt to treat any amblyopia.
*Surgery very unpredictable as the patient will want the eyes to converge and hence produce a unilateral esotropia in order to dampen the convergence.
What is secondary esotropia?
These are esotropias where the esotropia wasn’t the primary problem/ deviation.
This is an esotropia that develops as a result of loss or severe impairment of vision which may be unilateral or bilateral.
Sensory vision loss indicates vision problem occurred when?
between 6months- 7 years
Management of secondary esotropia?
*Treat cause of visual loss (This may obviously not be possible depending on the cause).
*Assess cosmetic appearance.
*Rarely any potential for BSV- poor unilateral VA is a barrier to fusion.
*Often requires botulinum toxin or surgery.
*Surgery results can be unpredictable in view of poor VA.
CONSECUTIVE ESOTROPIA meaning?
*This is an esotropia in a patient who initially had an exotropia/ exophoria.
*This is usually as a result of surgical overcorrection.
CONSECUTIVE ESOTROPIA characteristics?
*May complain of diplopia immediately but this often resolves.
*There may be limitations of abduction in cases where the overreaction was not planned (limited abduction implies the eye cannot move outwards normally. If this occurs the eye can turn in).
Management of consecutive esotropia?
- Relieve with prisms if troublesome.
- Treat any amblyopia
- Prescribe convex lenses if appropriate
- Surgery to resolve BSV (if potential)- to put patient back into suppression scotoma and improve cosmesis.
